1/2”Air Impact Wrench NO.:AE-12B01B2 Squire drive :1/2" Free speed: 8000r.p.m Bolt capacity:18mm Max torque:720 N.m(531ft-Ib) Hammer mechanism:twin hammer Air inlet:1/4" Air pressure: 6-8kg/cmZ Anvil length: 1” Moment bound :200-700 N.m